Freeradius as a loadbalancer - logging dropped accounting requests

[Aleš Rygl]

Hi Alan.

thanks for answers.

> > FR> > is using up to 140% CPU of 48 core system (256GiB RAM, SSD array) I
> > have reniced it and assigned real-time ionice class, the overall CPU of
> > the system is about 20%.
>   That's a huge system...

Yes, IMHO there is no lack of any kind of resources. I am going to try to move 
FR balancer instance to a different physical server just to be sure.

> >>  If you're losing packets at 1000 packets/s, FreeRADIUS is not the cause.
> > 
> > It must be a misunderstanding. The overall drop rate of LB is about
> > 4,6e-05 and drops are finally solved by a retransmission. I was just
> > wonder if there is a way how to detect/log drops or avoid them by config
> > optimisation.
>   There's no real way to do that.

OK

It is also strange that the drops (represented by retransmissions) are nearly 
independent on the average packet rate. I have the same amount of 
retransmissions at 2 a.m. (1k req/s) and at 4 p.m. (~4k req/s). Which is less 
than FR could just as a balancer IMHO do.

The they appear mainly at the top of the hour where we have spikes of 
concurrent accounting req. It looks like FR can handle quite high rate of 
steady load but the bottleneck could be in the amount of concurrent requests 
in spikes. 

Regards
Ales